Air conditioner units are conventionally utilized to adjust the temperature within structures such as dwellings and office buildings. In particular, one-unit type room air conditioner units may be utilized to adjust the temperature in, for example, a single room or group of rooms of a structure. A typical such air conditioner unit includes an indoor portion and an outdoor portion. The indoor portion is generally located indoors, and the outdoor portion is generally located outdoors. Accordingly, the air conditioner unit generally extends through a wall, window, etc. of the structure.
In the outdoor portion of a conventional air conditioner unit, a compressor that operates a refrigerating cycle is provided. At the back of the outdoor portion, an outdoor heat exchanger connected to the compressor is disposed, and facing the outdoor heat exchanger, an outdoor fan for cooling the outdoor heat exchanger is provided. At the front of the indoor portion of a conventional air conditioner unit, an air inlet is provided, and above the air inlet, an air outlet is provided. A blower fan and a heating unit are additionally provided in the indoor portion. Between the blower fan and heating unit and the air inlet, an indoor heat exchanger connected to the compressor is provided.
When cooling operation starts, the compressor is driven to operate the refrigerating cycle, with the indoor heat exchanger serving as a cold-side evaporator of the refrigerating cycle, and the outdoor heat exchanger as a hot-side condenser. The outdoor heat exchanger is cooled by the outdoor fan to dissipate heat. As the blower fan is driven, the air inside the room flows through the air inlet into the air passage, and the air has its temperature lowered by heat exchange with the indoor heat exchanger, and is then blown into the room through the air outlet. In this way, the room is cooled.
When heating operation starts, the heating unit is operated to raise the temperature of air in the air passage. The air, having had its temperature raised, is blown out through the air outlet into the room to heat the room.
In many currently known air conditioner units, the heating unit is formed from a plurality of heater banks. Each bank may have a different rated power output. The highest output for the unit generally occurs when all heater banks are operating at the same time. Additionally, many currently known air conditioner units have multiple blower fan speed settings. For example, a blower fan may in some cases be operated at a low setting or a high setting, or in some cases at various other intermediate settings.
One concern during operation of air conditioner units is overheating of the unit, particularly if a blockage occurs. For example, a blockage to the air inlet path and/or air outlet path prevents proper airflow from occurring within the unit. Particularly when all heater banks are on and the fan speed is low, temperatures within the unit can rise significantly, leading to deformation and/or other damage to components of the unit. Particularly vulnerable components include, for example, plastic components of the heater housing.
Accordingly, improved methods and apparatus for operating air conditioner units are desired. In particular, methods and apparatus that reduce or prevent overheating of the air conditioner unit would be advantageous.